2. Whisk together flour, baking powder, baking soda, and salt in a medium bowl. In a large bowl, beat butter and sugar on medium speed until creamy. Beat in eggs, vanilla, lemon zest, and ricotta until blended.

3. Add flour mixture and beat until combined. Cover and chill at least an hour.

4. Shape dough into balls, and place at least an inch apart on prepared cookie sheets.

5. Bake for 10 minutes, or until bottoms are light brown. Cool on baking sheet for about 1 minute, then transfer cookies to a wire rack to cool.

6. While cookies cool, prepare glaze: Stir together confectioners' sugar and lemon juice in small bowl until smooth. Drizzle glaze evenly over each cookie. Garnish with sprinkles if desired. Let stand until hardened.